The stats are now in, and the good news is that the on-time arrival rates for U.S. airlines actually improved last year, with some impressive performances.

Hawaiian Airlines brought more than 87% of its flights in on time. Delta also did very well at just above 83%, followed by Alaska and a surprise — Spirit Airlines. But what constitutes an on-time performance?

The metric for if a flight is deemed on time is if it gets to the gate within 15 minutes of scheduled arrival as opposed to what time it actually lands. And the airlines have been quietly padding their official flight times and are giving themselves cushions.

What this means is that in reality, almost all the on-time performance rates are somewhere between 60% and 70%. Take that into account the next time you book a flight and then schedule the rest of your day.